1. Field of the Invention
This invention is concerned with the breaking or resolution of oil-in-water (O/W) bituminous emulsions by treatment with ionenes.
2. Description of Related Art
A great volume of hydrocarbons exist in known deposits of tar sands. These deposits occur at various places, the Athabasca tar sands in Canada being an example. The petroleum in a tar sand deposit is an asphaltic bitumen of a highly viscous nature ranging from a liquid to a semi-solid. These bituminous hydrocarbons are usually characterized by being very viscous or even non-flowable under reservoir conditions by the application of driving fluid pressure.
Where surface mining is not feasible, the bitumen must be recovered by rendering the tar material mobile in-situ and producing it through a well penetrating the tar sand deposit. These in-situ methods of recovery include thermal, both steam and in-situ combustion and solvent techniques. Where steam or hot water methods are used, a problem results which aggravates the recovery of the bitumen. The difficulty encountered is emulsions produced by the in-situ operations. These emulsions are highly stable O/W emulsions which are made even more stable by the usual presence of clays. Most liquid petroleum emulsions are water-in-oil (W/O) types. These normal W/O emulsions are broken by methods known in the art. However, the bitumen emulsions which are O/W types present a much different problem, and the same demulsifiers used in W/O emulsions will not resolve the O/W bitumen emulsions.
A. C. W. W. Gewers, J. Canad. Petrol. Tech. 7(2), 85-90 (1968) describes the uniqueness of bitumen emulsions.
B. U.S. Pat. No. 3,928,448 claims an ionene for solids removal from water. O/W emulsion breaking is also mentioned.
C. U.S. Pat. No. 3,956,117 discloses the use of the same ionene as in B in breaking O/W emulsions, specifically oily water water emulsions.
D. U.S. Pat. No. 4,038,318 discloses the use of a three-dimensional ionene prepared from a dihalo compound and a Mannich base in breaking O/W emulsions.